Evo-MedAgent: Beyond One-Shot Diagnosis with Agents That Remember, Reflect, and Improve
Organizations: Technical University of Munich (TUM) · TUM University Hospital · LMU Munich · National University of Singapore ·
Abstract
Tool-augmented large language model (LLM) agents can orchestrate specialist classifiers, segmentation models, and visual question-answering modules to interpret chest X-rays. However, these agents still solve each case in isolation: they fail to accumulate experience across cases, correct recurrent reasoning mistakes, or adapt their tool-use behavior without expensive reinforcement learning. While a radiologist naturally improves with every case, current agents remain static. In this work, we propose Evo-MedAgent, a self-evolving memory module that equips a medical agent with the capacity for inter-case learning at test time. Our memory comprises three complementary stores: (1)~Retrospective Clinical Episodes that retrieve problem-solving experiences from similar past cases, (2)~an Adaptive Procedural Heuristics bank curating priority-tagged diagnostic rules that evolves via reflection, much like a physician refining their internal criteria, and (3)~a Tool Reliability Controller that tracks per-tool trustworthiness. On ChestAgentBench, Evo-MedAgent raises multiple-choice question (MCQ) accuracy from 0.68 to 0.79 on GPT-5-mini, and from 0.76 to 0.87 on Gemini-3 Flash. With a strong base model, evolving memory improves performance more effectively than orchestrating external tools on qualitative diagnostic tasks. Because Evo-MedAgent requires no training, its per-case overhead is bounded by one additional retrieval pass and a single reflection call, making it deployable on top of any frozen model.
Figures & tables
| Configuration | GPT-5-mini | Gemini-3 Flash | GPT-5.2 | |||
|---|---|---|---|---|---|---|
| MCQ | Open | MCQ | Open | MCQ | ||
| Baseline (Tool-Enabled) | 0.68 | – | 0.73 | – | – | |
| Baseline (Tool-Free) | 0.68 | 0.29 | 0.76 | 0.21 | 0.69 | |
| + (Procedural) | 0.71 | – | 0.81 | – | – | |
| + (Episodic) | 0.78 | – | 0.84 | – | – | |
| Full Memory ( + ) | 0.79 (0.76–0.82) | 0.40 | 0.87 | 0.38 | 0.81 | |
LLM Agent Self-Improvement
Large language model agent self-improvement studies how agents use experience and feedback to improve their behavior, tools, and workflows.
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